---
title: Connectivity Plus Usage
sidebar_label: Usage
hide_title: true
---

## Using Connectivity Plus

To start using Connectivity Plus, initialize the singleton, which will give you accesss to all methods in the API.

``` dart
final Connectivity _connectivity = Connectivity();
```

### Connection type

Using Connectivity API, you can find out which type of connection the device is using at the moment.

```dart
import 'package:connectivity_plus/connectivity_plus.dart';

final connectivityResult = await (Connectivity().checkConnectivity());

if (connectivityResult == ConnectivityResult.mobile) {
  // I am connected to a mobile network.
} else if (connectivityResult == ConnectivityResult.wifi) {
  // I am connected to a wifi network.
} else if (connectivityResult == ConnectivityResult.ethernet) {
  // I am connected to a ethernet network.
} else if (connectivityResult == ConnectivityResult.vpn) {
  // I am connected to a vpn network.
  // Note for iOS and macOS:
  // There is no separate network interface type for [vpn].
  // It returns [other] on any device (also simulator)
} else if (connectivityResult == ConnectivityResult.bluetooth) {
  // I am connected to a bluetooth.
} else if (connectivityResult == ConnectivityResult.other) {
  // I am connected to a network which is not in the above mentioned networks.
} else if (connectivityResult == ConnectivityResult.none) {
  // I am not connected to any network.
}
```

:::caution
Note that on **Android**, this does not guarantee connection to the Internet.
For instance, the app might have WiFi access but it might be a VPN or
a hotel WiFi with no access to internet.
:::

### Get Notified of Network Changes

In most use casses, you will probably use this package to know when your
user is connected to the internet or not, and for that you are provided
with a method that gives you the realtime status of the connection,
therefore enable and disable certain parts of your app that dependss on
user's connectivity.

#### 1. Declare a StreamSubscription

``` dart
StreamSubscription<ConnectivityResult> _connectivitySubscription;
```

#### 2. Listen to the Stream

Use `onConnectivityChanged` method that has a return type `Stream<ConnectivityResult>`,
to register a listener.

:::note
Note that connectivity changes are no longer communicated to Android apps
in the background starting with **Android 8.0**.
*You should always check for connectivity status when your app is resumed.*
The broadcast is only useful when your application is in the **foreground**.
:::

``` dart
// Initialize a variable with [none] status to avoid nulls at startup
ConnectivityResult connectivityResult = ConnectivityResult.none;

@override
void initState() {
  super.initState();
  _connectivitySubscription =
      _connectivity.onConnectivityChanged.listen(_updateConnectionStatus);
}

// Make sure to cancel subscription after you are done
@override
dispose() {
  subscription.cancel();
  super.dispose();
}
```

The listener will update the connectivity status.

``` dart
Future<void> _updateConnectionStatus(ConnectivityResult result) async {
  setState((){
      _connectionResult = result;
  });
}
```

:::caution
You should not be using the current network status for deciding
whether you can reliably make a network connection.
Always guard your app code against timeouts and errors that might come
from the network layer with `try/catch`.
:::

### [Web Only] Limitations

In order to retrieve information about the quality/speed of a browser's connection,
the web implementation of the `connectivity` plugin uses the browser's
[**NetworkInformation** Web API](https://developer.mozilla.org/en-US/docs/Web/API/NetworkInformation),
which as of this writing (Feburary 2021) is still "experimental", and not available in
all browsers:

![Data on support for the netinfo feature across the major browsers from caniuse.com](https://caniuse.bitsofco.de/image/netinfo.png)

On desktop browsers, this API only returns a very broad set of connectivity statuses (One of `'slow-2g', '2g', '3g', or '4g'`), and may *not* provide a Stream of changes. Firefox still hasn't enabled this feature by default.

**Fallback to `navigator.onLine`**

For those browsers where the NetworkInformation Web API is not available, the plugin falls back to the [**NavigatorOnLine** Web API](https://developer.mozilla.org/en-US/docs/Web/API/NavigatorOnLine), which is more broadly supported:

![Data on support for the online-status feature across the major browsers from caniuse.com](https://caniuse.bitsofco.de/image/online-status.png)

The NavigatorOnLine API is [provided by `dart:html`](https://api.dart.dev/stable/2.7.2/dart-html/Navigator/onLine.html),
and only supports a boolean connectivity status (either online or offline), with no network speed information.
In those cases the plugin will return either `wifi` (when the browser is online) or `none` (when it's not).
